SF 253 
.06 
1917 
"opy 1 



DAIRY LABORATORY 
MANUAL AND NOTE BOOK 

ERNEST L.ANTHONY B.S.A..M.S. 




Class _l£ 

Book 



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o 



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DAIRY LABORATORY 
MANUAL AND NOTE BOOK 



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DAIRY LABORATORY 
MANUAL AND NOTE BOOK 



COMPILED BY 

ERNEST L. ANTHONY, B.S.A., M.S. 

ASSISTANT PROFESSOR IN DAIRY HUSBANDRY, THE PENNSYLVANIA STATE COLLEGE 



15 ILLUSTRATIONS IN THE TEXT 



SECOND EDITION REVISED 




PHILADELPHIA AND LONDON 
J. B. LIPPINCOTT COMPANY 



SF 

• / 
If 17 



COPYRIGHT, I9I4, BY J. B. LIPPINCOTT COMPANY 
COPYRIGHT, 1917, BY J. B. LIPPINCOTT COMPANY 



Electrotyped and Printed by J. B. Lippincott Company 
At the Washington Square Press, Philadelphia, U. S. A. 



m 10 191? 

©CI.A4G0668 
/ - 



PREFACE 

The following exercises have been arranged especially for general courses 
in the Elements of Dairying. A number of these exercises have been used in 
separate form and have been brought together for courses of this nature. 
They are designed to cover the use of the Babcock Tester, Lactometer, and 
special work with Farm Separators and Churns. They have all been used by 
the writer in class work, a number of them were recommended by the Com- 
mittee on the Courses of Study of the Official Dairy Instructors' Association. 

These exercises are designed to be used with courses having two or 
more hours' laboratory practice each week, and should familiarize the student 
sufficiently with the general practice so that he may be able to handle the 
more advanced courses in testing and creamery work. The exercises are on 
separate pages so that the book may be used as a note book, and all answers 
and notations can be made while the student is in the laboratory. 

Ernest L. Anthony 
Pennsylvania State College, 
January 1, 1914 



CONTENTS 

PAGE 

Definitions 10 

Dairy Rules 11 

Rules for Standardization 12 

Exercise 1. — Object: To Determine the Physical Differences between Milk, Cream and 
Skimmilk 15 

Exercise 2. — Object: To Determine the Accuracy of the Calibration of the Glassware 
Used for the Babcock Test : 16 

Exercise 3. — Object: To Determine the Accuracy of the Calibration of the Glassware 
Used for the Babcock Test by the Trowbridge Plug Method; also a Method for 
Washing up Glassware 18 

Exercise 4.— Object: To Make a Test of Milk for Butterfat by the Babcock Method . 20 

Exercise 5. — Object: To Test Whole Milk for Fat Content by Babcock Method .... 22 

Exercise 6. — Object: To Test Cream for Fat Content by Babcock Method 23 

Exercise 7. — Object: To Test Cream for Fat Content by Babcock Method 24 

Exercise 8. — Object: To Determine the Percentage of Fat in Skimmilk and Whey. . . 25 

Exercise 9. — Object: To Determine the Percentage of Fat in Buttermilk 26 

Exercise 10. — Object: To Determine the Specific Gravity of Milk 27 

Exercise 11. — Object: To Determine the Total Solids and the Solids not Fat in Milk. . 29 

Exercise 12. — Object: To Determine the Specific Gravity and Adulteration of Milk.. . 30 

Exercise 13. — Object: To Determine the Effect of not Mixing a Sample Previous to 
Testing 32 

Exercise 14. — Object: To Determine Effect of Temperature when Reading the Fat 
Test 33 

Exercise 15. — Object: To Determine the Effect of Speed of the Tester upon the Test. . 34 

Exercise 16. — Object: To Determine the Effect of Varying Amounts of Acid in the 
Babcock Test 35 

Exercise 17. — Object: To Determine the Effect of Temperature of Milk and Incom- 
plete Mixing of Acid and Milk 36 

Exercise 18. — Object: To Determine the Effect of Measuring Cream as Compared 
with Weighing It 37 

Exercise 19. — Object: To Determine the Effect of Adding Water before Whirling 
in the 9-gram Cream Test : 38 

Exercise 20.— Object: To Test Butter for Percentage of Fat 39 



CONTE NTS— Continued 

Exercise 21. — Object: To Note the Acidity of Milk Products, and to Compare the 

Method of Determining the Acidity . . •• 40 

Exercise 22. — Object: To Standardize Milk and Cream 42 

Exercise 23. — Object: To Prepare a Commercial Starter 43 

Exercise 24. — Object: To Learn the Correct Use of Milk Coolers 44 

Exercise 25. — Object: To Make a Comparative Study of Cream Separators 45 

Exercise 26. — Object: Comparative Study of Separators 46 

Exercise 27. — Object: To Determine the Capacity of Separators 47 

Exercise 28.— Object: To Adjust Height of Bowl and Position of Cream Screw 48 

Exercise 29. — Object: To Determine the Effect of Speed Variations on the Proportion 
of Cream, Richness of Cream, and on the Loss of Fat in Skimmilk 49 

Exercise 30. — Object: To Determine the Influence of the Change of Inflow on the 
Proportion and Richness of Cream, and the Loss of Fat in the Skimmilk 50 

Exercise 31. — Object: To Determine the Effect of Variations in Temperature of Milk 
and Proportion and Richness of Cream and Loss of Fat 51 

Exercise 32. — Object: To Churn Butter from Ripened Cream. (First Churning Ex- 
ercise) 52 

Exercise 33. — Object: To Churn and Make a Good Grade of Butter from Well Ripened 
Cream. (Second Churning Exercise) 54 

Exercise 34. — Object: To See the Effect of Churning at a High Churning Temperature 
and Washing at a Low Temperature 55 

Exercise 35. — Object: To See the Effects of a Low Churning Temperature and a High 
Washing Temperature 56 

Exercise 36. — Object: To Determine the Effect of Churning very Thick Cream 57 

Exercise 37.— Object: To See the Effects of Over-working Butter 58 

Exercise 38. — Object: To Note the Effect of Over-churning on the Quality of the But- 
ter Produced 60 

Exercise 39. — Object: The Effect of Churning Cream at Different Stages of Ripening 62 

Exercise 40. — Object: The Scoring of Butter 64 

Exercise 41. — Object: To Determine the Percentage of Water in Butter 65 

Exercise 42.— Cottage Cheese 66 

Exercise 43. — Cross Section of Cream Separator Bowl 70 

Dairy Arithmetic Problems 71 



ILLUSTRATIONS 



PAGE 

Whole Milk Bottle : 16 

Pipette for Milk (17.6 cc.) 16 

Trowbridge Plug and Method of Using 18 

Correct Position for Filling Bottles 20 

Correct Manner of Taking Reading with Calipers 20 

Eight-bottle Hand Tester. Farm Size 21 

Correct Method of Taking Reading on Whole Milk Bottles. From the Ex- 
treme Lower Meniscus to the Top of the Upper Meniscus 21 

Small Laboratory Cream Scales 23 

Small Four-bottle Tester 24 

Skimmilk Bottle 25 

Lactometer 27 

Lactometer Cylinder 27 

Apparatus for Acid Test 40 

Farrington's Acid Test Apparatus 40 

Spring Balance for Weighing Milk 47 



DEFINITIONS 

Definition for Milk. — Normal milk is a liquid secreted by all healthy 
females of the mammalian group, for feeding their offspring. 

Definition for Specific Gravity.— The specific gravity of a substance is the 
relation between the weight of that substance and the weight of an equal vol- 
ume of distilled water. Water is always considered as one, or the unit, with 

which liquids and solids of the same temperature are compared. Examples: 
1 gallon of water weighs S.3 lbs. Specific Gravity 1. 

1 gallon of milk weighs S.55 lbs. " 1.032 

1 gallon of butterfat weighs 7.7 lbs. " " .93 

1 gallon of skimmilk weighs 8.58-lbs. " 1.034 

1 gallon of 20 per cent cream weighs 8.44 lbs. " " 1.012 

Definition of Centrifugal Force. — Centrifugal force is the outward pull or 

pressure brought on a wheel or object when rotating and being whirled from 
the centre. The centrifugal force is increased (a) directly in proportion to 
the decrease in the diameter (the velocity remaining the same), and (b) 
directly with the square of the velocity (diameter being constant). 



DAIRY LABORATORY MANUAL 
AND NOTE BOOK 



DAIRY RULES. 

1. Rule for determining the number of pounds of butterfat in a given 
amount of cream or milk when the percentage of fat is given. 

Multiply the percentage of butterfat by the pounds of milk and divide 
by 100 (i.e., point off two places). 

2. Rule for determining the percentage of casein in milk when the per- 
centage of fat is known. (Van Slyke.) 

Subtract 3 from the percentage of fat in milk, multiply the remainder 
by .4 and add 2.1 to the result. 

Milk with 4.8 per cent fat has 2.82 per cent casein [(4.8-3) x.4+2.1 = 
2.82]. 

3. Rule for determining the price per pound received for butterfat in 
cream when the percentage of fat and the price per gallon are given. 

Multiply the pounds of cream in a gallon by the percentage of fat given 
(point off two places). This will give the pounds of fat one gallon of cream 
contains. Divide the number representing the price per gallon of cream by 
the number of pounds of butterfat, the quotient will equal the price per pound 
of butterfat. 

4. Rule for determining the price of a gallon of cream when it is being 
paid for on the butterfat basis. 

Multiply the percentage of fat in the cream by the pounds of cream in 
a gallon (point off two places). This will give the number of pounds of fat 
in a gallon. Multiply this by the price per pound paid for fat. 

5. Rules for finding the percentage of solids not fat. 

Rule A. — (A rough practical rule.) The (Quevenne) lactometer reading 
plus the percentage of fat divided by 4 equals the solids not fat. 

Rule B. — (Accurate rule, recommended for accurate work.) 

One fourth of the (Quevenne) lactometer reading plus .2 times the fat 
equals the solids not fat. 

If the lactometer reading is 31 and the fat is 3.8 per cent the solids not 
fat equal 8.51 per cent. (314-4+ .2X3.8 = 8.51.) 



(12) DAIRY RULES (Continued) 

6. Rule for finding the percentage of acid by Mann's acid test. 
Multiply the number of cc. of alkali solution used, by .009 and divide 

the product by the number of cc. of the sample tested, the quotient when 
multiplied by 100 will give the percentage. 

7. Rule for finding the percentage of overrun in butter. 

Subtract from the butter made, the pounds of fat in the cream used. 
Divide the result by the butterfat in the cream and multiply by 100. This 
equals the percentage of actual overrun. 

If 450 pounds of butter is made from cream containing 400 pounds of 
fat, the pounds of overrun is (450 — 400 = 50) . The percentage is [(50 -r- 400) X 
100 = ] 12.5 per cent. 

8. To find the correct specific gravity of a sample when the temperature 
is other than 60° F. 

Add one-tenth of a per cent to the reading for each degree above 60°, 
and subtract one-tenth for each degree below 60°. 

RULES FOR STANDARDIZATION. 

In many cases it is necessary to change the per cent fat in milk or cream 
to some other known per cent fat. This is called standardizing. In 
much standardization work it is necessary to find the relative amount 
of two different milks or creams of different percentages of fat to make a 
certain amount of standardized milk or cream of a known per cent of fat. 
This is found by: 

9. Subtracting the difference between the fat desired in the standard- 
ized milk, and the milk of the lower fat content; and by subtracting the 
difference between the percentage of fat in the milk of the lower fat content 
and the percentage of fat in the milk or cream of the higher fat content. 
The first result when divided into the last will give the percentage of the 
amount wanted which must be used of the milk or cream of the higher fat 
content. This amount taken from the total amount wanted will give the 
amount of the lower milk or cream to be used, as: 

100 pounds of 3.5 per cent milk is desired. It is to be made from milk 
testing 3 per cent and milk testing 5 per cent. 

3.5-3 = .5; 5-3 = 2. .5^-2 = .25. 25 per cent, or 1/4 of the mixture, 
must be of the 5 per cent milk and 75 per cent of it must be of the 3 per cent 
milk. 100^-25 = 75 pounds of the 3 per cent milk to be used; 25 pounds of 
the 5 per cent milk to be used. 



DAIRY RULES (Continued) 



(13) 



10. The parallelogram method of standardization was devised by Pro- 
fessor R. A. Pearson, and is illustrated as follows: 




In the rectangle let A always represent the percentage of fat wanted in 
the standardized milk. Let B represent the per -cent of fat in the milk or 
cream of the higher fat content. Let C represent the per cent of fat in the 
milk or cream of the lower fat content. The proportion D is secured by 
subtracting C from A; and the proportion E is secured by subtracting A 
from B. D represents the proportion of B to be taken, and E represents the 
proportion of C to be taken. 

These proportions give the parts of the milk or cream of the different 
percentages of fat which when added together in these proportions will give 
the desired percentage of fat in the standardized milk or cream. These pro- 
portions when added together and divided into the amount desired will give 
in pounds the value of each part. This multiplied by the number of parts 
found in each proportion will give the number of pounds of each to use. 
To illustrate: 

B = 22 — — D = 1 = parts of 22%. 




18 = parts of 3% 

95 pounds of 4 per cent milk is desired. It is to be made from milk 
testing 3 per cent and cream testing 22 per cent. 

18+1 = 19 parts. 95-^19= 5. 5 represents the value in pounds of 
one part or proportion. Then 5 x 18 =90 pounds of 3 per cent to use. 5x1 = 
5 pounds of 22 per cent to use. 

1 1. Where milk is to be reduced by adding skimmilk. 

By dividing the percentage of fat in the milk wanted by the percentage 
of fat in the milk on hand will give the percentage or the amount of the milk 
to be used, and the rest must be added as skimmilk. Thus: 

300 pounds of 5 per cent milk is to be mixed with skimmilk to form 4 
per cent milk. (4-r-5 = .80.) Then 300 pounds represents 80 per cent of the 



(14) DAIRY RULES (Continued) 

mixture wanted, and the rest, or 20 per cent, equals the amount that must 
be added as skimmilk. 20 per cent of 300 = 75. 300+75 = 375 pounds of 
the standardized milk. 

12. Where milk is to be raised to a higher per cent of fat by adding milk 
or cream of a still higher fat content. 

Subtract the percentage of fat in the milk on hand which contains the 
lower fat content from the percentage desired in the standardized product. 
Take the difference between the percentage of fat in the milk or cream of 
the higher fat content and the desired percentage of fat in the standardized 
milk. Divide the first result by the second, and the result represents the 
part of the milk or cream of the higher per cent fat to be used. Multiply 
this result by the pounds of milk which contains the lower per cent fat, and 
this will give the amount of the richer milk to add. This, added to the amount 
of the milk with the lower fat content, will give the total amount standardized. 
Thus: 

300 pounds of 3 per cent milk is to be made to test 3.5 per cent by adding 
5 per cent milk. (3.5 per cent — 3 per cent = .5; and 5 per cent — 3.5 per 
cent = 1.5); .5^-1.5 = .33 1/3; 300 x.33 1/3 = 100. Use 100 pounds of 5 per 
cent milk with 300 pounds of 3 per cent milk, or a total of 400 pounds of 
3.5 per cent standardized milk. 

13. By dividing the per cent of fat in the standardized milk into the 
percentage of fat in the milk on hand and multiplying the result by the num- 
ber of pounds of the milk on hand will give the number of pounds of the 
standardized milk which can be made from the milk on hand. If the quantity 
of the standardized milk is less than the amount on hand, then the difference 
must be taken out as skimmilk; if greater, it must be added as skimmilk. 
To illustrate: 

300 pounds of 3.5 milk will make how many pounds of 4 per cent milk? 
3.4-^4 =.850; .850X300 = 255 pounds of 4 per cent milk which can be 
secured, or 300—255 = 45 pounds of skimmilk to be removed. 

14. When it is desired to determine the number of pounds of standard- 
ized milk a quantity of milk of a lesser per cent of fat will make. 

Find the pounds of butterfat in the quantity of milk by multiplying 
the pounds of milk by the per cent (point fat off two places). Then by 
dividing this result by the percentage fat desired in the standardized milk 
and multiplying the result by 100 will give the number of pounds of stand- 
ardized milk. Thus: 

300 pounds of 3.5 milk contains (300 x3.5 = 10.5) pounds fat. This 
would make (10.54-4 xlOO = 262.5) pounds of milk testing 4 per cent. 



Grade 
Date . 



EXERCISE 1. (15) 

Object. — To determine the physical differences between milk, cream and 

skimmilk. 
Apparatus. — Samples of milk, cream, and skimmilk, beakers, and micro- 
scopes. 
Note to Instructors.— Slides of skimmilk, whole milk, and cream should be prepared 
previous to the class period, and adjusted in the microscope, as students in first taking 
up this work will not be familiar enough with the different apparatus to properly 
make up the slides. 

Step 1. Study the differences found in the appearance of the sample of the 

milk, cream, and skimmilk. 
Step 2. Study the field under the first microscope. Note the size, the shape, 

and the color of the fat globules. 
Step 3.' Study the field under the second microscope. Note the number of 

fat globules compared with those in the field of the first microscope. 

Note their size and shape. 
Step 4. Study the field under the third microscope. Note the size and 

shape of the globules compared with those of the second microscope. 
Step 5. Draw one of the fields in the space of this page. Write up the steps 

at the bottom of this page, explaining all the differences noted in the 

three fields. 



Grade 
Date • 



(16) 




EXERCISE 2. 

Object. — To determine the accuracy of the 
calibration of the glassware used for the 
Babcock test. 

Apparatus. — Set of bottles used for test, and 
burette. Sheet of filter paper. 

Step 1. Burette Method.— Fill the bottle to be 
tested to the zero mark with water. By 
means of a strip of filter paper remove 
any water adhering inside the neck above 
the zero mark. Measure into the bottle, 
from an accurate burette, 1 cc. of water. 
If the bottle is correct this should bring 
the water to the 5 per cent mark. Another 
cc. from the burette should bring the 
water to the 10 per cent mark. 

In case of the cream bottles, if 9 gram 
bottles are used, 1 cc. of water will fill the 
bottle to the 10 per cent mark, or 5 cc. to 
50 per cent mark. 

Test all bottles by this method, re- 
cording all data. 

Step 2. Accuracy of the Pipette. — Allow 17.6 cc. 
of water from the burette to run into a 
pipette, the bottom of which is closed 
with the finger. If correct the water will 
be at the 17.6 cc. mark. 

Any glassware showing more than .2 
per cent error should not be used. 



Whole milk bottle. 17.6 cc. pipette 
for milk. 



EXERCISE 2 (Continued) 
Data. 



(17) 



Style of bottle 


Bottle No. 


Water by 
measure 


Variation 5% 
mark 


Water by 
measure 


Variation at 
upper mark 








1 ' ' 


1 - 




i i ! 











Pipette 



Grade 
Date . 






J 

I 



a 



w 



(18) EXERCISE 3. 

(^ Object. — To determine the accuracy of the cali- 

bration of the glassware used for the Babcock 
test by the Trowbridge plug method; also a 
method for washing up glassware. 
Apparatus. — Set of bottles used for the test, set of 
Trowbridge (or Nefus) plugs, sheet filter paper. 

Part 1. Trowbridge Method.— Fill the bottle to the 
zero. With filter paper, dry the neck inside 
above the zero mark. Insert the plug until 
the water rises half way between the two sec- 
tions. In a correct bottle the surface will be 
at 5 per cent. Lower the plug until the upper 
portion is 1/8 inch below the surface. The 
water should be at the 10 per cent mark. 
Record all data. 

Part 2. All glassware should be thoroughly washed 
and be always left clean at the end of each 
laboratory period. Take a dish pan of warm 
water and put in it about two tablespoonfuls 
of some good washing powder. Put the bot- 
tles in the suds thus formed and let the bottles 
fill about half full of the hot solution. Then 
take bottles in each hand and shake well. 
After they have been washed as well as pos- 
sible in this manner use a small bottle brush 
to clean out the necks of the bottles. Take 
them out of the water and rinse with clean warm water. Use this 
same method for all other glassware. This method if carefully used 
will always keep all glassware in the best possible condition. Care and 
attention should be given to always have all apparatus in the 
best possible shape. 




Trowbridge plug and 
method of using. 



EXERCISE 3 (Continued) 
Data. 



(19) 



Style of bottle 


Bottle No. 


Variation 5% mark ■ Variation at upper mark 






! 












' 





































































Grade . 
Date. . 



(20) 



EXERCISE 4. 



Object. — To make a test of milk for butterfat, by the Babcock method. 
Apparatus. — Two whole milk bottles; a 17.6 cc. pipette; acid measure; 

acid; sample of whole milk; two sample bottles; hot water bath. 
Step 1. Practice using the pipette 

with water until you can 

reasonably adjust the 

amount to be taken; Caf 

17.6 cc. i8y 




Correct position for filling bottles. 



Step 2. Always have milk between 60° and 70° F. before drawing sample 

with pipette. 
Step 3. Mix the milk thoroughly by pouring from one vessel into another 

before drawing sample. Always pour down the side of the vessel. 
Step 4. Put 17.6 cc. of milk into each of two whole milk bottles. Allow the 

milk to run down along the neck by holding the pipette and bottle 

at an angle of about 60°. (Letter one sample "A" and the other "B".) 
Step 5. To each bottle add 17.5 cc. of sulphuric acid (1.82 to 1.83 s. g.), 

using an acid measure. Turn bottle slowly as acid is added, allowing 

acid to run down the sides of the neck. 



EXERCISE 4 (Continued) 



(21) 



Step 6. Agitate each bottle until the curd is all dissolved, by giving it a 
rotary motion as soon as acid is added. 

Step 7. Put them into a centrifugal machine, whirl five minutes, fill to the 
neck with water about 130° F., whirl two minutes, fill to about the 9 
per cent mark, whirl one minute. Set in hot water bath 130°-140° F 
with water around necks for 5 minutes, then read fat. 

Note. — Read the whole milk test from the top of the upper meniscus to the bottom 
of the lower meniscus. 

Report. 



Bottle No A 


B 




%fat 





1. Below give reasons for having the milk at 60° to 70°. 

2. Why is the milk poured from one vessel to another 
before sampling? 

3. Explain the ac- 
tion of acid in the test. 

4 Why should each 
sample of milk be tested 
in duplicate? 

5 What is the color 
of the fat column? 



Eight-bottle hand tester. Farm size. 






- 




~~1 


B 


^-6 




-Si. *> 




±-5 




§-4 




E^3 


A 


=r-Z 




~1 




~0 







Correct method 
of taking reading 
on whole milk 
bottles. From 
the extreme lower 
meniscus to the 
top of the upper 
meniscus. 



Grade . 
Date.. 



(22) 



EXERCISE 5. 



Object. — To test whole milk for fat content by Babcock method. 

Repeat Exercise 4. Test as many samples of milk as possible during the 
laboratory period. 

Report. 



Bottle No 












% fat. ■! A 










1b 













1. Try to account for any difference in tests between samples "A" and 
"B" in each case. 

2. What would be the pounds of butterfat given by a cow giving 8000 
pounds of milk per year with the fat test of your first sample? 

3. What would be its total value at 38 cents a pound? 

4. Why is 17.6 cc. of milk used for the test? 

5. Why are the bottles set in water at 130° F. before reading? 



Grade . 
Date.. 



EXERCISE 6. 



(23) 



Object. — To test cream for fat content by Babcock method. 
Apparatus. — Two cream bottles ; acid 

measure; acid; 17.6 cc. pipette; 

sample of cream; two mixing 

beakers; scales; hot water bath. 
Step 1. Mix sample of cream thor- 
oughly by pouring from one 

beaker to another, care being 

taken not to churn it. 
Step 2. Balance cream bottle A on 

scales and weigh into it 9 grams 

of cream. Duplicate in bottle B. 
Step 3. Measure out about 9 cc. of 

water at 60° to 70° for each cream 

bottle. Add to each bottle. 
Step 4. Measure out 17.5 cc. of acid 

for each bottle and complete test 

as for whole milk. 

Note. — Read cream test from bottom of fat column to bottom of top meniscus. 

Report. 




Small laboratory cream scales. 



Bottle No 


| 










% fat \ A 


i 






\b 









At the bottom of the page explain — 

1. Why read cream columns different from milk. 

2. Why cream is weighed out instead of being measured out, as is done 
with milk. 

3. Why 9 cc. of water is added before the acid. 



Grade 
Date . 



(24) 



EXERCISE 7. 



Object. — To test cream for fat content by Babcock method. 

Repeat Exercise 6. Run as many samples as possible, during laboratory 
period. 

Report. 



Bottle No 






















%!M ii 











































At the bottom of the page ex- 
plain — 

1. How many pounds of fat in 
1875 pounds of cream with a test 
of the first sample? 

2. What was the color of the 
fat in the column? Any variation? 

3. What would happen if the 
acid were added before the water? 

4. Why is 9 grams used for a 
sample. 

5. When cream is weighed does 
it have to be at a temperature of 
from 60° to 70°? 




Small four-bottle tester. 



Grade 
Date. . 



EXERCISE 8. 



(25) 



Object. — To determine the percentage of fat in skimmilk 

and whey. 
Apparatus. — Samples of each, skimmilk and whey; skimmilk 

bottles; pipette; acid measure; mixing beakers; acid; hot 

water bath. 
Step 1. Measure out 17.6 cc. first of skimmilk in each of two 

skimmilk bottles. 

Proceed as for whole milk test except use a little in excess 

of 17.5 cc. of acid. 
Step 2. Repeat test in the same manner using whey instead 

of skimmilk. 



Skimmilk 
Bottle. 






Re-port. 



Skimmilk bottle No.. . j 


















% of fat \ - 

C B 






































Whey bottle No 


















% of fat {- 

C B 


1 




! 

























At the bottom of the page explain — 

1. Why is a different bottle used for whole milk than skimmilk? 

2. Why is a little more acid used than in the whole milk test? 

3. How many pounds of fat in 1700 pounds of skimmilk with the above 
test? In 2500 pounds of whey with the above test? 



Grade 
Date . 



(26) 



EXERCISE 9. 



Object. — To determine the percentage of fat in buttermilk. 

Apparatus. — Sample of buttermilk; two skimmilk bottles; two whole milk 

bottles; pipette; acid measure; mixing beakers, and acid. 
Step 1. Measure out first 17.6 cc. of buttermilk in each of the skimmilk 

bottles; also make up duplicate tests of buttermilk in whole milk bottles, 

as buttermilk may be too high in fat content for skimmilk bottles. 
Step 2. Complete the tests as before. Read the test which is the most 

accurately measured. 

Report. 



Buttermilk in skim- 
milk bottle No.. . . 




















■| 


% of fat ]- 

C B 












































Buttermilk in whole 
milk bottle No.. . . 
























% of fat || 













































At the bottom of the page explain — 

1. Why are two sets of bottles used for the buttermilk test? 

2. Why is a little more acid used than with the whole milk test? 

3. How many pounds of fat in 1700 pounds of buttermilk with the above 
test? (Show operation.) 



Grade 
Date. . 



EXERCISE 10. 



(27) 



Object. — To determine the specific gravity of milk. 

Apparatus. — Lactometer; lactometer cylinder; thermometer, and sample 

of milk. 
Step 1. Thoroughly mix sample of milk and regulate temperature between 

60° and 70° F. 
Step 2. Fill cylinder nearly full of sample of milk. Place lactometer in 

sample and observe exact reading on lactometer after it has become still. 

Caution. — Care is necessary to not let the lactometer drop in the 

cylinder, as the lactometer is very easily broken. 
Step 3. Record exact temperature of sample and lactometer reading. 
Step 4. Test sample by Babcock method for fat content. 




Lactometer cylinder. 



(28) 



EXERCISE 10 (Continued) 
Re-port. 



Sample No. 


Temperature 


Lactometer reading 


Reading corrected for 
temperature 


%fat 








| 1 








| 




























' 




' 












J 1 ' 







1. Calculate the solids not fat and the total solids from the above data. 
(For figuring total solids and solids not fat see rules 5, A 'and B.) 

2. What are solids not fat? 

3. What is the specific gravity of normal cows' milk? 

4. Why is it necessary to make the correction in the lactometer when 
the temperature is other than 60°? 

5. When milk is heated, what is the effect on its specific gravity? 

6. How does cooling milk affect the specific gravity? 



Grade 
Date • 



EXERCISE l: 



(29) 



Object. — To determine the total solids and the solids not fat in milk. 
Apparatus.— Babcock test outfit; lactometer and equipment; a sample of 

whole milk. 
Step 1. Regulate temperature of whole milk sample until near 60° F. Pour 

into cylinder and carefully take lactometer reading. 
Step 2. Make a Babcock test for fat. Record all data, and by rules 5, A and 

B figure out the total solids and solids not fat for the sample. Repeat 

for a second sample. 





Report. 










Lac. reading correct- 
ed for temp. 


1 

% fat 

A B 


Solids not fat 


Total solids 


Sample No. 1 




Sample No. 2 . . • 1 




! 



1. What wouM be the total solids in a sample having a lactometer 
reading of 32.6 at 68° F. and a fat test of 3.8 per cent? 

2. How many pounds of solids not fat in 400 pounds of this milk? 



Grade 
Date . 



(30) 



EXERCISE 12. 



Object. — To determine the specific gravity and adulteration of milk. 

Apparatus. — Two samples adulterated with water; one normal sample; 
lactometer and cylinder; thermometer; test outfit; mixing beakers. 

Step 1. Proceed as in Exercise 11. 

Step 2. Record data, figure out solids not fat, whether samples are adulter- 
ated or not. If adulterated, nature and percentage of adulteration. 

Report. 



Sample 
No. 


Temp. 


Laet. 
reading 


Corrected read- 
ing 


; fat 


Solids not 
fat 


Adulterant 
used 


% adultera- 
tion 














































1 
1 






















1 


























































1 








































• 











EXERCISE 12 (Continued) (31) 

1. Calculate the solids not fat in a sample of milk testing 3.6 per cent 
fat, with a lactometer reading of 34 at 52° F. 

2. What are the solids not fat in a sample of milk testing 2.8 per cent 
fat, with a lactometer reading of 26 at 60° F.? 

3. Is this sample adulterated? 

4. If this sample has been adulterated, what has probably been used 
as an adulterant? 

5. What makes you think this? 



Grade 
Date. . 



(32) 



EXERCISE 13 



Object. — To determine the effect of not mixing a sample previous to testing. 
Apparatus. — Sample of milk that has stood for an hour or two without 

being stirred; the Babcock test outfit. 
Step 1. Without disturbing the sample of milk on the desk, draw two samples 

from the top. 
Step 2. Draw two samples from the bottom. 
Step 3. Mix the milk thoroughly by pouring; take two samples. 
Step 4. Add proper amount of acid to each, mix and complete the tests. 

Report. 





Before mixing 








T( 


>P 


Bottom 






A 


B 


A 


B 


A 


B 


Bottle No 












% of fat 













1. Explain below what would be the losses to a creamery receiving 
45,000 pounds of milk daily if the above careless methods were used in test- 
ing the samples, supposing the sample was taken from the top. 

2. What loss to patron if sample is taken from bottom? 

3. What would be the percentage of error in the above tests? 



Grade 



Date 



EXERCISE 14. 



(33) 



Object. — To determine effect of temperature when reading the fat test. 
Apparatus.— Sample of cream; whole milk; skimmilk; Babcock test outfit. 
Step 1. Measure out two bottles of whole milk, two of skimmilk. Put 9 

grams of cream into each of two cream bottles. 
Step 2. Add proper amounts of acid, mix and complete the tests. 
Step 3. Take reading as soon as whirling is complete. 
Step 4. Temper the water bath to 200° F. Insert the bottles so the water 

comes near the top. After being inserted five minutes, read. 
Step 5. Lower the water to 150° F., after five minutes read. 
Step 6. Lower to 130° F. and, after five minutes, read. 
Step 7. Lower the water to 90° F. and, after five minutes, read. 

Report. 





Whole milk 


Skimmilk 


Cream 




A J B 


A 


B 


A i B 


Bottle No 














First reading % 
fat 


















200° % fat 














150° % fat 














130° %fat 










90° %fat 






! 





1. Which is the proper reading and why? 

2. What would be the loss to a creamery taking in 30,000 pounds of 
cream if the test was read, as in step 4, at 200°? 

3. What loss to patron if read, as in step 7, at 90°? 

4. Give variation in the color of the fat at the different stages. 



Grade 



Date 



(34) 



EXERCISE 15. 



Object. — To determine the effect of speed of the tester upon the test. 
Apparatus. — Samples of whole milk; skimmilk; Babcock test outfit. 
Step 1. Prepare three test samples of whole milk. 

Note. — In this exercise have all conditions alike except speed. 

Step 2. Prepare three test samples of skimmilk using skimmilk bottles. 
Step 3. To the skimmilk add a little more than a full measure of acid. Mix 

as usual. 
Step 4. Run one bottle of whole milk and one of skimmilk at half speed; 

one of each at proper speed; one of each at high speed. 





Report. 






Speed 


Whole milk % fat 


Skimmilk % fat 














At proper speed 





















At the bottom of the page explain — 
1„ The effects on the color of the fat. 

2. Other effects of insufficient speed. 

3. Other effects of too much speed. 



Grade 
Date . 



EXERCISE 16. (35) 

Object. — To determine the effect of varying amounts of acid in the Babcock 

test. 
Apparatus. — Sample of whole milk; Babcock outfit. 
Step. 1. To one sample add the regular measure of acid. 
Step 2. To another add half the regular amount of acid, 8.8 cc. 
Step 3. To another add 1 1/2 measures of acid, 26.3 cc. 
Step 4. Mix and test in the usual way. 

Report. 





Regular measure 


Half measure 


1 1/2 measure 


Bottle No 












% fat 













1. What is the effect of insufficient acid? 

2. Of too much acid? 

3. Write a full description of clearness, color and correctness. 



Grade 



Date 



(36) 



EXERCISE 17. 



Object. — To determine the effect of temperature of milk and incomplete 
mixing of acid and milk. 

Apparatus. — Sample of whole milk; Babcock test outfit. 

Step 1. Measure out two samples, add acid at once and mix thoroughly, 
(usual method). 

Step 2. Measure out two samples, place in water bath at 130° for ten min- 
utes; then add acid and rotate to dissolve curd. 

Step 3. Measure out two samples, add acid but allow same to stand ten 
minutes before dissolving curd. 

Step 4. Complete all tests. 

Report. 





Usual method 


Too hot 


Stood too long 




A 


B 


A 


B 


A B 


Bottle No 














% fat 



















Explain below — 

1. The effect of having the sample too hot before adding the acid. 

2. The effects of allowing the sample to stand with the acid on it before 
mixing. 

3. Give the different colors of fat in the tests above and give reasons 
for these changes. 



Grade 



Date 



EXERCISE 18. 



(37) 



Object. — To determine the effect of measuring cream as compared with 

weighing it. 
Apparatus. — Sample of cream; Babcock outfit; 2 9-gram and 4 18-gram 

cream bottles. 
Step 1. Measure into each of two 18-gram bottles 17.6 cc. of cream. 
Step 2. Add 17.5 cc. of acid, rotate well and allow to stand until mixture 

turns black, then add hot water up to the neck of the bottle. 
Step 3. Weigh out 18 grams of cream into each of two 18-gram bottles. 

Add acid and water as in step 2. 
Step 4. Weigh into each of two 9-gram bottles 9 grams of cream and test 

in the usual manner. 

Report. 





17.6 cc. cream IS grams cream 


9 grams cream 




ABA 


B 


A B 


Bottle No 














% fat 























1 . Which test should be the correct one? 

2. Give the advantages and disadvantages of weighing out cream for 
a test. 

3. With how many pounds of fat would a cream patron be over-credited 
if he delivered 467 pounds of cream and was allowed the highest test? 

4. How much would he be short if paid by the lowest test, butter being 
worth 30 cents per pound, overrun being 14 per cent? 



Grade 



Date. 



(38) 



EXERCISE 19. 



Object. — To determine the effect of adding water before whirling in the 

9-gram cream test. 
Apparatus. — Sample of cream; Babcock test outfit. 
Step 1. Weigh into each of two 18-gram bottles 18 grams of cream. 
Step 2. Weigh into each of two 9-gram bottles 9 grams of cream. 
Step 3. Add the proper amount of acid to each lot. After standing a few 

minutes add hot water to one half of each lot. 
Step 4. Mix and finish the tests. 

Re-port. 





18 grams 
no water 


18 grams 
with water 


9 grams 
no water 


9 grams 
with water 




A 


B 


A 


B 


A B 


A 


B 


Bottle No. 
















% fat 

















Write a full description of the variations in the above tests with reasons 
for (a) color, (b) clearness, and (c) correctness of the fat test. 



Grade 
Date . 



EXERCISE 20. 



(39) 



Object. — To test butter for percentage of fat. 

Apparatus. — Sample of butter; Babcock test outfit. 

Step 1. Preparing sample.— Put a fair sample into a tightly stoppered 
bottle. Put the bottle into water at 95° F. and shake thoroughly until 
melted. Then put the bottle into cold water and shake well until butter 
becomes of a thick, creamy consistency. From this sample small por- 
tions may be taken for testing. 

Step 2. Testing. — Weigh 9 grams of butter into each of two bottles gradu- 
ated to 50 per cent, add 10 cc. of hot water, and about 8.5 cc. of acid. 
Mix until all the curd is dissolved. Add hot water to bring the fat into 
the neck of the bottle. Whirl in a centrifuge for five minutes and read. 
The reading multiplied by 2 will be the correct test. 

Report. 





A 


B 


A 


B 


A 


B 


A 


B 


A 


B 


Bottle No 


















% fat 





















1. If butter contains 80 per cent fat what should be the percentage of 
overrun? 

2. What is the average composition of butter? 

3. What is the percentage of butterfat allowed by law? 



Grade 



Date 



(40) 



EXERCISE 21. 



Object. — To note the acidity of milk products, and to compare the method 

of determining the acidity. 
Apparatus. — Sample of milk; cream; cheese; skimmilk; buttermilk; Far- 

rington's, Mann's and Van Norman's apparatus; solution for acidity 

tests. 
Step 1. Follow the printed directions for the particular test being used. 

(See rule 6.) 




Apparatus for acid test 



Farrington's acid test apparatus. 



EXERCISE 21 (Continued) 
Report. 



(41) 





Percentage acidity 


Mann's 
Degrees 


Calculate % 
by Mann's 


Sample 


Farrington's 


Van Norman's 


Milk A 










Milk B 














Cream A 






Cream B 








Skimmilk A.. . . 








Skimmilk B. . . . 










Buttermilk A . . 










Buttermilk B . . 










Cheese A 








Cheese B 









Write the advantages and disadvantages of each test. 



Grade 



Date. 



(42) 



EXERCISE 22 



Object. — To standardize milk and cream. 

Apparatus. — Sample of milk and cream; Babcock test outfit; sample 

bottles; cream scales. 
Step 1. Run test for fat on both cream and milk samples. 
Step 2. Standardize 100 grams of 4 per cent milk from the tested cream and 

whole milk samples. 
Step 3. Standardize 100 grams of 20 per cent cream from the tested whole 

milk and cream samples. 
Step 4. Run fat tests on all standardized samples and record data. 







Report. 










B 


Step 2. Grams used 


Step 3. Grams used 


Bottle No . . 




Milk 


Cream 


Milk 








Cream 


Test of whole milk 














Test of cream 














Test after step 2 

































Work out the following problems — 

1. One thousand pounds of 3.6 per cent milk is to be raised to 4 per 
cent milk; how much skimmilk must be taken out? 

2. How much 30 per cent cream and skimmilk must be used to make 
up 1000 pounds of 25 per cent cream? 

3. How much 36 per cent cream and 3.6 per cent milk must be used to 
make up 800 pounds of 25 per cent cream? 

4. How many pounds of 40 per cent cream and 4 per cent milk must be 
used to make up 90 pounds of 20 per cent cream? 



Grade 
Date. . 



EXERCISE 23. (43) 



Object. — To prepare a commercial starter. 

Apparatus. — A pint bottle, sterilized; a sample of commercial starter; a 

sterilized graduated cylinder; a sample of pasteurized skimmilk; a 

thermometer. 
Step 1. Measure out 25 cc. of the commercial starter into a sterilized pint 

bottle. Add to it 225 cc. of pasteurized skimmilk at a temperature of 

80° F. 
Step 2. Place cover on bottle and set away in starter box at a temperature 

of 70° F. for 24 hours. Hold at this temperature until all changes have 

been noted. 
Step 3. Record all the changes which a starter undergoes from the time it is 

made up until observations are complete. 

1. Write a full description of a starter and all the changes which take 
place in its manufacture. 

2. Explain as fully as possible the reasons for each change. 

3. Give briefly the advantages of using a starter. 



Grade 



Date 



(44) 



EXERCISE 24. 



Object.— To learn the correct use of milk coolers. 

Apparatus.— Quantity of water or milk; milk cooler; supply of milk cans- 
thermometers. • ' 

Step 1. Weigh out 100 pounds of the milk or water and have the tempera- 
ture about that of milk when taken from the barn, 90°. Place in the 
cooler vat. 

Step 2. Arrange the cold water inflow to give full flow, take the temperature 
o, inflow, of outflow, and length of time to cool the milk to 50° and the 
amount of water needed. Record data below. 

Step 3. Same as step 1 and 2 except have water passing through the cooler 

with only half pressure. Record data. 
Step 4. Same as step 1 and 2, only determine the length of time and amount 
of water necessary to cool to within 3 degrees of the temperature of the 
water. Take temperature of inflow and outflow in all cases. 









Report. 










Temp. 

milk 


Temp. 

inflow 


Temp, 
outflow 


Time 


Amt. water 
required 


Temp, when 
cooled 


Step 2 














Step 3 














Step 4 















Grade 



Date 



EXERCISE 25. 

Object.— To make a comparative study of cream separators. 

Apparatus. — Separators in separator room. 

Steps. Study several separators and fill the record columns correctly. 

Record. 



(45) 





1 






1 








. 
























4. Revolutions of bowl per one turn oi 














































































































12 Weight of bowl. . 














13. Bowl No. . 














14. Height of top of receiving tank from 














15. Height of crank spindle from floor 










16. Height of crank handle from floor at 


























































20. Pressure of worm gear, down or up? . . 









Write a criticism of each machine studied — give its special advantages 
and its disadvantages. 



Grade 
Date . 



(46) 



EXERCISE 26. 



Object. — Comparative study of separators. 

Apparatus. — Separators in separator room. 

Procedure. — Carefully remove the neck bearing which is located in the 
upper seating for the bowl. Study the character of the bearing with 
regard to the points indicated below. When through, carefully replace 
and adjust the bearings before leaving the machine. Follow the same 
instructions for the bottom bearing which is located at the lower seat- 
ing of the spindle. 

Report. 



of separator 



Neck-bearing 

Character of spring; crown, spi- 
ral, wire or ribbon; adjustable 
or non-adjustable? 



Bottom-bearing 
Flat or sharp, pin on point, or 
both, or balls? Is it a weight- 
carrying or guide-bearing? Ad- 
justable as to height? 



At the bottom of the page make criticism as to ease of removing and 
replacing the bearings, of each of the machines studied. 



Grade 



Date 



EXERCISE 27. 

Object. — To determine the capacity of separators. 

Apparatus. — Two large dippers; 2 fourteen quart pails; a quan- 
tity of milk. (Two or more students may work together.) 

Step 1. See that the milk is at the right temperature, 90° to 
98° F., and that there is a sufficient amount to maintain 
a full flow during the experimental run. Start separat- 
ing, and catch the first cream and skimmilk in dippers. 
When the milk is running a normal flow, take the dippers 
away and let the skimmilk and cream run into the regu- 
lar pails for exactly one minute. Take them away and 
let the rest of the milk run into the dippers. Weigh 
up the amount of skimmilk and cream which was 
caught in the one-minute experimental run. Compute 
the capacity per hour. Flush bowl with warm rinse 
water. Save samples of skimmilk and cream. 




Spring balance for 
weighing milk. 



Report. 



1. Name of separator. 



2. Size. 



3. Rated capacity per hour 

4. Note speed of handle three times 

5. Temperature of milk at start ; at finish 

6. Pounds of skimmilk, 1 min.; 1 hour. 

7. Pounds of cream, 1 min. ; 1 hour . 

8. Pounds of skimmilk and cream, ... 1 min.; 1 hour. 



Below show how long it would take each day to separate the milk from 
thirty cows, each giving 35 pounds daily, with a machine of a capacity of 
the above machines. 



Grade 



Date 



(48) 



EXERCISE 28. 



Object. — To adjust height of bowl and position of cream screw. 

Apparatus. — Separators in separator room; quantity of whole milk. 

Step 1. Name of separator. 

Step 2. See that height of bowl is such as to deliver skimmilk and cream 
into their respective covers without touching them. Before making any 
adjustment, study direction sheet for this machine thoroughly. 

Step 3. With sufficient milk (or water) in supply can to maintain full flow, 
separate at least one gallon, shut off supply, weigh and compute what 
proportion the cream is of the total amount separated. 

Step 4. Adjust cream screw to make the amount of cream between 12 and 14 
per cent of the total separated. 

Step 5. If already correct, adjust so as to make a change of between 4 and 6 
per cent, 

Re-port. 





1st trial 2nd trial 


3rd trial 














Cream, pounds 

































Explain below — 

1. How much change was made in the cream screw? 

2. How does the cream screw affect the amount of cream? 

3. How does it affect the amount of fat? 

4. When water is separated, would the amount of water leaving the 
cream spout be the same as the amount of cream when milk is separated? 

5. Give reason for your answer. 



Grade 
Date . 



EXERCISE 29. 



(49) 



Object. — To determine the effect of speed variations on the proportion N of 
cream, richness of cream, and on the loss of fat in skimmilk. 

Apparatus. — Separators in separator room; quantity of whole milk. 

Step 1. Have milk at 90° to 98° F. 

Step 2. Separate half the milk at regular speed. 

Step 3. Separate remaining half with speed reduced one-third. 

Step 4. Save sample of whole milk; also samples of cream and skimmilk 
from both two and three. 

Report. 



Name of separator Size . 





First trial 


Second trial 




1st half 


2nd half 


1st half 2nd half 




























Note speed three times 
































Pounds skimmilk and cream . . . 


















































Test of skimmilk 












Pounds butterfat in milk 






Pounds butterfat in skimmilk . . 








Pounds butterfat in cream 






Pounds fat unaccounted for .... 






% fat unaccounted for 




i 



Write the reasons and effects of the variations that you have found in 
this exercise. 



Grade 



Date 



(50) 



EXERCISE 30. 



Object. — To determine the influence of the change of inflow on the propor- 
tion and richness of cream, and the loss of fat in the skimmilk. 

Apparatus. — Separators in separator room; quantity of whole milk. 

Step 1. Separate half the milk with faucet wide open and speed uniform. 

Step 2. Separate the other half, starting with faucet wide open, then close 
till cream becomes noticeably thicker. 

Note. — Maintain correct and uniform speed. Save samples and test. 

Report. 



Name of separator Size . 





First trial 


Second trial 




1st half 


2nd half 


1st half 2nd half 


Pounds of milk used 






















Note speed three times 


































Pounds skimmilk and cream . . . 






























Test of cream 








Test of skimmilk 














Pounds butterfat in milk 








Pounds butterfat in skimmilk . . 








Pounds butterfat in cream 






Pounds fat unaccounted for ... . 






% fat unaccounted for 




1 1 



Write the reasons and effects of the variations that you have found in 
this exercise. 



Grade 
Date • 



EXERCISE 31. 



(51) 



Object. — To determine the effect of variations in temperature of milk and 

proportion and richness of cream and loss of fat. 
Apparatus. — Separator in separator room; quantity of whole milk. 
Step 1. Separate half the milk at about 90° F. 
Step 2. Separate half the milk at about 50° F. 

Note. — Maintain correct and uniform speed. Save samples and test. 



Report. 



Name of separator Size . 





First trial 


Second trial 




1st half 


2nd half 


1st half 


2nd half 






























Note speed three times 


































Pounds skimmilk and cream . . . 








































' 




















Pounds butterfat in milk 




Pounds butterfat in skimmilk . . 





Pounds butterfat in cream 



Pounds fat unaccounted for , 



% fat unaccounted for 



Write the reasons and effects of the variations that you have found in 
this exercise. 



Grade 
Date • 



(52) EXERCISE 32. 

Object. — To churn butter from ripened cream (first churning exercise). 
Apparatus. — Churn; cream; scales; thermometer; pails; salt; color; etc. 
(Two or more students may work together in all churning exercises.) 

Note. — Students going into the laboratory should first note the work to be done, 
which will be found on the slip on the bulletin board or on the blackboard. 

General Instructions for Churning. — The principle of churning is the proper agitation 
of the cream that the butterfat which is in it is properly and thoroughly separated out. 

Before churning, the cream should be properly ripened. That is, it should have been 
held at the proper temperature that the right amount of acidity may have developed in it. 

The cream should have an acidity of from .3 to .5 per cent and be held at the tempera- 
ture required for churning at least two hours before churning. The churning temperature 
will necessarily vary in the different seasons, but should run about 52-54 in the summer 
and 54-58 in the winter. 

The churn should be thoroughly scalded out to remove bad odors or taints and then 
cooled down with cold water. The cream should then be weighed and placed in the churn . 
and the churning process started. 

If a barrel churn, churn until the butter begins to break in small granules about the 
size of a grain of corn. Here the churning should stop. It should take not over 30 minutes 
to reach this stage if the cream was properly handled before starting to churn. If it takes 
less than 15 minutes it may mean that the churning temperature was too high. 

Draw off the buttermilk through a sieve that the small particles of butter may not 
be lost. Take the temperature of the buttermilk. Pour over the butter, in the churn, 
about the same amount of water as cream used in the churning and from 4° to 10° cooler 
than the buttermilk. Rinse the butter in this water for about 15 to 20 revolutions of the 
churn. Draw off the water, and take the butter out on the working board and salt, using 
about one ounce of salt to the pound of butter. The salting may be done in the churn if it 
has a worker. 

After salting, allow the salt to dissolve, then work the butter until the salt is in all 
parts and the buttermilk is out. Print and wrap in clean parchment paper. 

Wash and scald all utensils and leave hot to dry. 

Student A. Weigh out the cream for churning; get the temperature right, 
add butter-color if necessary, place cream in churn ; make all necessary 
observations, record data; scald the butterworker and other wooden- 
ware and then chill thoroughly with cold water; get the necessary 
rinse water and have it at the right temperature. Weigh the salt and 
have things ready when churning is done. Draw off buttermilk, rinse 
butter, place butter on worker, salt, work and print. Finish recording 
data. (Record all data on the following page.) 

Student B. Scald the churn with hot water and then chill thoroughly with 
cold water. Run the churn, take samples of buttermilk and wash up 
the churn. In washing up the churn rinse with luke-warm water and 
then wash thoroughly with scalding water and washing powder and 



EXERCISE 32 (Continued) (53) 

scald with clear water. Use brush on the outside of the churn. Leave 
the churn hot. Wrap the butter, wash the butterworker, other wooden- 
ware, and pails in the same manner as the churn was washed. See that 
the floor is clean and dry and that each piece of apparatus is clean and 
in its place. Unclean or misplaced apparatus will count heavily against 
good butter making. 



CHURNING RECORD.— Churning No 

This blank should be neatly and accurately filled out when the product is finished. 

Condition of cream Pounds cream 

Total pounds of fat 

Temperature at which cream was ripened 

Time to ripen 

Length of time held at churning temperature 

% of fat in cream when churned , 

Kind and size of churn used 

Approximate fullness of churn 

Temperature churned 

Time to churn 

Amount of color used 

Size of granules when churning stops 

Temperature of buttermilk Test 

Amount of wash water 

Temperature of wash water 

Amount of salt used 

Brine or dry salted 

Butter from churn hard or soft 

Pounds of butter 

Pounds of overrun . 

% overrun 

Work and observations by 

Assisted by 

Make special notes regarding this churning operation. 



Grade 
Date. 



(54) EXERCISE 33. 

Object. — To churn and make a good grade of butter from well ripened' 

cream. (Second churning exercise.) 
Apparatus. — The same as for Exercise 32. 
Step 1. Follow closely Exercise 32. (The two students may trade work.) 



CHURNING RECORD.— Churning No 

This blank should be neatly and accurately filled out when the product is finished. 

Condition of cream Pounds cream 

Total pounds of fat . 

Temperature at which cream was ripened 

Time to ripen 

Length of time held at churning temperature 

% of fat in cream when churned 

Kind and size of churn used 

Approximate fullness of churn 

Temperature churned 

Time to churn 

Amount of color used 

Size of granules when churning stops 

Temperature of buttermilk Test 

Amount of wash water 

Temperature of wash water 

Amount of salt used 

Brine or dry salted 

Butter from churn hard or soft 

Pounds of butter 

Pounds of overrun 

% overrun 

Work and observations by 

Assisted by 

Make special notes regarding this churning operation. 



Grade 
Date . 



EXERCISE 34. (55) 

Object. — To see the effect of churning at a high churning temperature and 

washing at a low temperature. 
Apparatus. — Same as for other, churning exercises. 
Step 1. Have temperature of cream at 58° to 60° F., rinse water 45° to 50°. 



CHURNING RECORD.— Churning No 

This blank should be neatly and accurately filled out when the product is finished. 

Condition of cream Pounds cream 

Total pounds of fat 

Temperature at which cream was ripened 

Time to ripen 

Length of time held at churning temperature 

% of fat in cream when churned 

Kind and size of churn used 

Approximate fullness of churn 

Temperature churned 

Time to churn 

Amount of color used 

Size of granules when churning stops 

Temperature of buttermilk Test 

Amount of wash water 

Temperature of wash water 

Amount of salt used 

Brine or dry salted 

Butter from churn hard or soft 

Pounds of butter 

Pounds of overrun '. 

% overrun 

Work and observations by 

Assisted by 

Make special notes regarding this churning operation. 



Grade 
Date . 



(56) EXERCISE 35. 

Object. — To see the effects of a low churning temperature and a high wash- 
ing temperature. 
Apparatus.— Same as for other churning exercises. 
Step 1. Have cream at 48° to 50° F.; rinse water 56° to 58°. 

Write fully the evil effects of the above practice. 



CHURNING RECORD.— Churning No 

This blank should be neatly and accurately filled out when the product is finished. 

Condition of cream Pounds cream 

Total pounds of fat 

Temperature at which cream was ripened 

Time to ripen 

Length of time held at churning temperature 

% of fat in cream when churned 

Kind and size of churn used 

Approximate fullness of churn 

Temperature churned 

Time to churn 

Amount of color used 

Size of granules when churning stops 

Temperature of buttermilk Test 

Amount of wash water 

Temperature of wash water 

Amount of salt used. . . . : 

Brine or dry salted 

Butter from churn hard or soft 

Pounds of butter 

Pounds of overrun 

% overrun 

Work and observations by 

Assisted by 

Make special notes regarding this churning operation. 



Grade 
Date . 



EXERCISE 36. (57) 

Object. — To determine the effect of churning very thick cream. 
Apparatus. — Same as for other churning exercises. 
Step 1. Have cream 35 to 40 per cent fat. 



CHURNING RECORD.— Churning No 

This blank should be neatly and accurately filled out when the product is finished. 

Condition of cream Pounds cream 

Total pounds of fat 

Temperature at which cream was ripened 

Time to ripen 

Length of time held at churning temperature 

% of fat in cream when churned 

Kind and size of churn used 

Approximate fullness of churn 

Temperature churned , 

Time to churn 

Amount of color used 

Size of granules when churning stops 

Temperature of buttermilk Test 

Amount of wash water 

Temperature of wash water ■ 

Amount of salt used 

Brine or dry salted 

Butter from churn hard or soft i 

Pounds of butter 

Pounds of overrun 

% overrun 

Work and observations by 

Assisted by 

Make special notes regarding this churning operation. 



Grade 
Date , 



(58) EXERCISE 37. 

Object. — To see the effects of over-working butter. 

Apparatus. — Same as in other churning exercises. 

Step 1. Churn and otherwise care for the cream as in the first churning 
exercises until the butter is ready to work. 

Step 2. Work butter until it seems to be worked enough; note its condition. 
Break a few lumps and note the grain. Then continue working, noting 
the condition of the butter every five revolutions of the worker. Con- 
tinue working until the butter is much over-worked. Record data. 

Report. 

Well worked 

Additional 5 revolutions 

10 revolutions 

15 revolutions 

20 revolutions 

25 revolutions 

30 revolutions 

35 revolutions 

Make special notes regarding this churning operation. Make record on 
following page. 



EXERCISE 37 (Continued) (59) 



CHURNING RECORD.— Churning No 

This blank should be neatly and accurately filled out when the product is finished. 

Condition of cream Pounds cream 

Total pounds of fat 

Temperature at which cream was ripened 

Time to ripen 

Length of time held at churning temperature 

% of fat in cream when churned 

Kind and size of churn used 

Approximate fullness of churn 

Temperature churned 

Time to churn 

Amount of color used 

Size of granules when churning stops 

Temperature of buttermilk Test 

Amount of wash water 

Temperature of wash water 

Amount of salt used 

Brine or dry salted 

Butter from churn hard or soft 

Pounds of butter 

Pounds of overrun 

% overrun 

Work and observations by 

Assisted by 

Make special notes regarding this churning operation. 



Grade 
Date . 



(60) EXERCISE 38. 

Object. — To note the effect of over-churning on the quality of the butter 
produced. 

Apparatus. — Same as in other churning exercises. 

Step 1. Proceed as in a regular churning until butter comes the size of corn 
grain. Then continue churning until the butter has collected in large 
masses. Finish churning operations as usual. Record data on the fol- 
lowing page but make observations on this page. 

1. What will be the effect on the keeping quality of the butter when 
over-churned? 

2. What constituents of the butter will likely be raised in their per- 
centage? 

3. Will more or less working of the butter be required to remove the 
buttermilk from butter that has been over-churned? 

4. Will the grain, or texture, be thus improved or would it be more 
"salvy"? 

5. What caution would you give regarding the extent of churning for 
butter that is to be stored and shipped long distances? 



EXERCISE 38 (Continued) (61) 



CHURNING RECORD.— Churning No 

This blank should be neatly and accurately filled out when the product is finished. 

Condition of cream Pounds cream 

Total pounds of fat 

Temperature at which cream was ripened 

Time to ripen 

Length of time held at churning temperature 

% of fat in cream when churned , 

Kind and size of churn used 

Approximate fullness of churn 

Temperature churned 

Time to churn 

Amount of color used 

Size of granules when churning stops 

Temperature of buttermilk Test 

Amount of wash water 

Temperature of wash water , 

Amount of salt used 

Brine or dry salted 

Butter from churn hard or soft 

Pounds of butter 

Pounds of overrun 

% overrun 

Work and observations by 

by 

Make special notes regarding this churning operation. 



Grade 
Date. 



(62) 



EXERCISE 39. 



Object. — The effect of churning cream at different stages of ripening. 
Apparatus. — Same as for other churning exercises, with cream as described 

in the following note. 

Note to Instructor.— Divide the class of students into about four 
groups, and have previously prepared four equal churnings of cream, part 1, 
fresh unripened, part 2, having .2 per cent of acidity, part 3, with .4 per cent 
acidity, and part 4, with as high as .7 per cent if possible. Have the cream 
all of the same percentage of fat and same temperature. Each group should 
churn the cream under the same conditions and in the same type of churn. 

The data and results should be recorded on the following page. The 
differences in the churnings for the different groups should be recorded below. 



Part No. 


Time required for 
churning 


% fat in butter- 
milk 


Flavor of butter 


1. Fresh cream 






2. .2% acid 








3. .4% acid 












4. About .7% acid 









1. Can you discover evidence of curds in any of the lots of butter after 
working? 

2. Which lots would probably keep best, if stored for some time? 



EXERCISE 38 (Continued) (63) 



CHURNING RECORD.— Churning No 

This blank should be neatly and accurately filled out when the product is finished. 

Condition of cream Pounds cream 

Total pounds of fat 

Temperature at which cream was ripened 

Time to ripen 

Length of time held at churning temperature 

% of fat in cream when churned 

Kind and size of churn used 

Approximate fullness of churn 

Temperature churned 

Time to churn 

Amount of color used 

Size of granules when churning stops 

Temperature of buttermilk Test 

Amount of wash water 

Temperature of wash water 

Amount of salt used 

Brine or dry salted • 

Butter from churn hard or soft 

Pounds of butter 

Pounds of overrun 

% overrun 

Work and observations by 

Assisted by 

Make special notes regarding this churning operation. 



Grade 



Date 



(64) 



EXERCISE 40. 



Object. — The scoring of butter. 

Apparatus. — Several samples of butter; score card; butter triers; paper, etc. 

Step 1. Read carefully the score card and become thoroughly familiar with 
its points. . 

Step 2. Wipe trier carefully and insert into butter near centre of the pack- 
age. Withdraw carefully, note condition of butter on the trier; also 
take the aroma of the sample. 

Step 3. Take a part of the trier-full between the tongue and the roof of the 
mouth and let dissolve slowly, noting the flavor, salt, taints, etc. Record 
observations. 

Report. 



Student's score 



Flavor 

Body 

Color 

Salt 

Package 



Flavor 


45 


Body 


25 


Color 


15 


Salt 


10 


Package 


5 



Flavor 

Body 

Color 

Salt 

Package 



Give the reasons for the off flavors and defective body that may have 
been found in the above samples. 



Grade 
Date . 



EXERCISE 41. 



(65) 



Object. — To determine the percentage of water in butter. 

Apparatus. — Set of balances; samples of butter; some type of moisture 

test device as the Ames, Irish, or Marshall test. 
Step 1. Put samples of butter in clean dry bottles or jars with tight lids or 

caps, warm up, but do not entirely melt the sample, until it can be 

thoroughly mixed. Mix. 
Step 2. Carefully weigh out 10 grams of the sample into a heated, weighed 

dish or cup; heat over the flame or in an oven at 175° to 180° F., until 

it ceases to lose weight. 
Step. 3. Take the difference between original weight and final weight and 

compute the percentage of moisture. 

Report. 





Original weight 


Final 


weight 


1 Loss in weight 


% of moisture 


Sample No. 1 . ; 






Sample No. 2 






•Sample No. 3 







Sample No. 4 



Grade. 
Date. . 



(66) EXERCISE 42. 

Cottage Cheese 

Use good skimmilk direct from separator. Heat to 75° or 80°, in cans 
or vat. After the required temperature has been reached add starter, two 
to eight pounds per 100 pounds milk, the more starter used the quicker 
it will set. As soon as it is set or coagulated heat it slowly up to 95°. 

If a dry cheese is desired heat up to 100° or 108°, but if a moist cheese 
is desired heat only to 90° or 93°. The object of heating is to aid in 
expelling the whey. The curd will settle to the bottom of the can. Transfer 
the contents of the can or vat on to a strainer or into a cheese cloth bag and 
let excess whey drain off. Stir curd occasionally so that it does not dry next 
to cloth or strainer. 

As soon as the whey is properly drained off, salt by using 1 pound of 
salt to 100 pounds of curd. It is best not to salt cottage cheese too heavily 
as most people would rather salt to satisfy their taste. Salt retains the 
keeping quality of cottage cheese. 

Write full description of cheese made and note any special changes 
observed. 



Grade. 
Date. . 



(70) EXERCISE 43. 

Cross Section of Cream Separator Bowl 

Note. — Select any typical cream separator and draw to a suitable 
scale an accurate cross section of the bowl. Neatly label all parts. In addi- 
tion to this trace carefully the inflow of whole milk, thru the area of separa- 
tion and thru the outflow of cream and skimmilk. Any explanations necessary 
to make this drawing clear should be made at bottom of page. 



DAIRY ARITHMETIC PROBLEMS. - (71) 

1. What is the percentage of total solids in milk testing 4.9 and having 
a lactometer reading of 33 at 57° F.? 

2. What would be the correct specific gravity of a sample of milk if the 
lactometer gave a reading of 32.5 at 65° F.? 

3. What is condition of each of the following samples: 

(a) Lactometer reading 32 at 58° F., and has 4 per cent fat. 

(b) Lactometer reading 33 at 63° F., and has 2.5 per cent fat. 

(c) Lactometer reading 27.4 at 69° F., and has 2.4 per cent fat. 

4. How many pounds of solids not fat in 139 pounds of milk testing 3.9 
per cent fat and having a lactometer reading of 29 at 69° F.? 

5. How many pounds of total solids are there in 49 pounds of milk 
having a fat test of 4.17 per cent and a lactometer reading of 32.4 at 56° F.? 

6. How many pounds of milk testing 3 per cent must be mixed with 
140 pounds cream, testing 27 per cent, to make milk testing 5.1 per cent? 

7. Two thousand pounds of milk testing 3.5 per cent fat, is to be made to 
test 4 per cent by adding milk that tests 5 per cent. How many pounds will 
be added? 

8. One thousand pounds of cream testing 30 per cent is to be reduced to 
20 per cent by adding whole milk testing 4 per cent. How many pounds of 
the milk must be added? 

9. One thousand pounds of cream testing 30 per cent is to be reduced 
to 25 per cent by adding milk testing 2.5 per cent. How many pounds of 
the milk must be added? 

10. One thousand pounds of cream testing 30 per cent is to be reduced 
to 25 per cent by adding skimmilk. How many pounds of skimmilk must be 
added? 

11. Six hundred pounds of 30 per cent cream is wanted. Having cream 
on hand testing 40 per cent, and skimmilk, find how many pounds of each 
are needed to produce 600 pounds of 30 per cent cream. 

12. How many pounds each of 50 per cent cream and 25 per cent cream 
must be mixed together to produce 1,000 pounds of cream testing 40 per cent? 

13. One thousand pounds of cream testing 50 per cent is to be diluted to 
make it test 40 per cent, using cream testing 25 per cent. How many pounds 
of the 25 per cent cream must be added to give the desired test? 

14. One thousand pounds of cream testing 25 per cent is to be raised 
to 40 per cent with cream testing 50 per cent. Find how many pounds of 
the 50 per cent cream must be added to the 25 per cent cream to make it 
test 40 per cent. 



(72) » DAIRY ARITHMETIC PROBLEMS (Continued) 

15. Received 800 pounds of butterfat in 20,000 pounds of 4 per cent 
milk. From this 975 pounds of butter was made. Find the true overrun, 
expressed both in percentage and in pounds. 

16. Received 800 pounds butterfat which made 984.94 pounds of butter; 
allowing 1 per cent for mechanical losses, what was the percentage of over- 
run, after mechanical losses were deducted? 

17. Received 800 pounds butterfat. Made 984.94 pounds butter. Loss 
1.25 per cent. What was the overrun? 

18. Butterfat received 800 pounds; butterfat in butter made 80.41 
per cent. What is the overrun? 

19. What is the percentage of overrun when 176 pounds fat makes 194 
pounds butter? What is the percentage of fat in this butter? 

20. What is the percentage of overrun if 1800 pounds of cream testing 
33 per cent makes 667 pounds of butter. 

21. If you had 15 pounds of butterfat in cream that is to be churned 
and 18 pounds of butter was made, what is the percentage of overrun? 

22. If 1800 pounds of cream testing 33 per cent made 650 pounds of 
butter, what is the number of pounds overrun? The percentage of overrun? 

23. How many pounds of butter would you get from 1000 pounds of 
cream, testing 23 per cent and having an overrun of 14 per cent? 

24. When butterfat sells for 40 cents per pound, how much must be 
secured for 4 per cent milk wholesale to realize the same? Buttermilk and 
skimmilk selling for 25 cents per hundred. 

25. From which of these methods of selling will the largest returns be 
secured? (a) 4 per cent milk at $1.55 per hundred; (b) 20 per cent cream 
selling for 80 cents per gallon, with skimmilk worth 25 cents per hundred; 
(c) butter selling for 40 cents per pound, buttermilk and skimmilk at 25 
cents per hundred, and an overrun of 18 per cent being secured; charges 
for butter manufacture being one and one-half cents per pound of butter. 



LIBRARY OF CONGRES 



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